South Korea said on Saturday a bird flu outbreak at a poultry farm was caused by the highly virulent H5N1 strain of the virus, in the country's first case for three years of the infection that can kill humans.
The Agriculture Ministry said earlier this week it suspected bird flu had killed 6,000 chickens at a farm in the southwest of the country that lies on a path for migratory birds.
"It is the H5N1 strain," a ministry official said by telephone on Saturday, after test results.
The ministry ordered the culling of 236,000 poultry within a 1,640-foot radius of the farm in North Cholla province about 100 miles from Seoul, a ministry statement said.
Quarantine authorities also banned the shipment of more than 5 million poultry from 221 farms within a 6.2-mile radius of the farm.
No people appear infected
There were no reports to suggest local residents or quarantine officials had been infected, another Agriculture Ministry official said by telephone.
Between December 2003 and March 2004, about 400,000 poultry at South Korean farms were infected by bird flu.
During that outbreak, the country culled 5.3 million birds and spent about $1.6 billion on preventing the disease spreading, officials said.
Subsequent testing in the United States indicated at least nine South Korean workers involved in the cull had been infected with the H5N1 virus, but none developed major illnesses.
Since 2003, outbreaks have been confirmed in around 50 countries and territories, according to the World Organization for Animal Health.
North Korea had an outbreak at poultry farms near the capital Pyongyang in February 2005, which led it to cull more than 200,000 chickens and vaccinate 1.1 million poultry.
The World Health Organization said that by Nov. 13, there had been 258 cases of human infection of the H5N1 strain since 2003, killing 153 people. Many of the victims were Asians, with 98 deaths in Vietnam and Indonesia, WHO said.